Phase II study of trifluridine/tipiracil (FTD/TPI) and oxaliplatin as induction chemotherapy (IC) in resectable esophageal and gastroesophageal junction adenocarcinoma (EGAC)

TPS464 Background: Neoadjuvant chemoradiation (CRT) followed by surgery is a standard approach for localized EGAC. Despite multimodality treatment, 5-year overall survival (OS) is less than 50%, with pathologic complete response (pCR) rates of 20%. Achievement of pCR is associated with an improved OS. We propose to use a novel combination of FTD/TPI and oxaliplatin as IC. We hypothesize that IC before CRT will increase the pCR rate in localized EGAC. Methods: This is an open-label, multicenter phase II trial. Patients (pts) with potentially resectable loco-regional EGAC are eligible. Pts. should have adequate organ function, ECOG performance status of 0 –1, age < 76 years, and endoscopic ultrasound-determined node-positive disease with any T-stage, or T3-T4a with any N stage. Pts. with T4b or M1 disease will be excluded. Pts. will receive three cycles of IC with FTD/TPI and oxaliplatin. Based on the maximum tolerated dose (MTD) observed in a phase I trial, FTD/TPI will be administered 35 mg/m² BID, days 1–5 every 14 days, with a fixed dose of oxaliplatin 85 mg/m² (day 1). Pts will then undergo concurrent CRT (standard radiation dose of 5040 cGY will be utilized) with weekly Carboplatin (AUC 2) and Paclitaxel (50 mg/m2) for 6 weeks followed by surgery. Our primary objective is to evaluate the pCR rate. The secondary objectives include evaluation of 2-year disease-free survival (DFS), 2-year OS, and assessment of toxicities of the IC. As a correlative endpoint, circulating tumor DNA level will be correlated with disease recurrence and metabolic response on PET CT. Assuming a historic pCR rate of 20% with standard CRT, 41 pts (enrollment of up to 45 pts accounting for non-evaluable pts) are needed to show a 15% increase in pCR with IC with 80% power at one-sided significance level of α = 0.1. In stage 1, n1= 22 evaluable pts will be enrolled. If there is 5 or more pCRs, an additional n2= 19 pts will be enrolled in stage 2. If 12 or more pCRs are observed in the total n = 41 evaluable pts, then the proposed treatment regimen will be considered promising for further study. We anticipate accrual over a 2-year period from 3 sites. Clinical trial information: NCT04097028.